Wave machine to initiate scavenging of internal combustion



April 27, 1965 M. BERcHToLD 3,180,077

WAVE MACHINE TO INITIATE SCAVENGING OF INTERNAL COMBUSTION Filed March 20, 1962 4 Sheets-Sheet 1 ,47' Ama/emr Pee-.sauna Paer- ,4/

April 27, 1965 M. BERcHToLD 3,180,077

WAVE MACHINE TO INITIATE SCAVENGING OF INTERNAL COMBUSTION Filed March 20, 1962 4 Sheets-Sheet 2 April 27, 1965 M. BERCHTOLD 3,180,077

WAVE MACHINE TO INITIATE SCAVENGING OF INTERNAL COMBUSTION I Filed March 20, 1962 4 'Sheets-Sheet 4 E U g, E ,'li

I A INVEN TOR.

/W/l/Y iff/970A@ EE- 5- BY f aisee?? Ice Patentes nps. 27, rees 3,130,977 WAVEMACHENE 'i ENTRATE SCAVENGMG OF EN'ERNAL CMBUSTEUN Max Berchtold, Kusnacht, Switzerland, assigner to l-T-E Circuit Breaker Company, Phiiadelplria, Pa., a corporation ot' Pennsylvania Filed Mar. 2t), 1962, Ser. No. 181,0S3 8 Claims. (Cl. ntl-iS) My invention relates to the combination of a wave iachine and internal combustion engine and, more particularly, is directed to a novel arrangement whereby the wave machine provides the necessary differential of pressure across the cylinders of a reciprocating engine to thereby initiate scavenging operation of the cylinders at the correct time.

My novel arrangement provides a common intake manifold for all of thecylinders of the reciprocating engine but has multiple subdivided exhaust manifolds to combine undivided cylinders of the reciprocating engine connected in such a manner as to obtain the best scavenging effect. The wave machine has accordingly a suitable number of inlet ports each inlet port being operatively connected to each of the exhaust manifolds. With this novel arf rangement a particular wave machine utilizes the blowdown energy of one cylinder of one group in order to initiate the scavenging of a cylinder of another group.

Aerodynamic wave machines have been used as superchargers for reciprocating engines and particular examples and constructions of same are disclosed and described in US. Patent 2,957,304 issued October 25, 1960, to Max n Berchtold entitled Aerodynamic Wave Machine Used as a Supercharger for Reciprocating Engines and assigned to the assignee of the instant invention.

1t is the essence of the aforementioned U.S. Patent 2,957,364 to utilize the blow-down energy of a first cylinder to thereby provide input energy for the wave machine, which wave machine in turn provides an increase in pressure which, in turn, laids the scavenging of the same or another cylinder depending on the manifold arrangement. Although'this arrangement has been found to be extremely desirable in numerous applications, it has nevertheless been found that under certain operating conditions, as for example in low load operation, the timing of the wave machine may be disturbed so that the output of the wave machine-may not supply suicient clean air to the reciprocating engine. It is possible that the compressed air at the pickup port of the Wave machine is contaminated by some of the exhaust gasses from the reciprocating engine. It is noted that even at other operating conditions there is always some degree of contamination of the high pressure output air at the pickup port of the wave machine.

in an internal combustion engine considerable amount of energy is lost as kinetic energy in the exhaust gases.

At the time the expansion stroke of the piston has been completed the pressure in the cylinder is considerably higher than the ambient pressure, It is difficult to build turbines capable to extract this energy effectively. In order to support the scavenging, particularly at low load, the amount of this energy is small; therefore high utiliza- 'on is essential to maintain desirable operating conditions without any other scavenging pumps or blowers driven from the engine. The various means such as piston pumps, Roots-blowers, turbo-blowers, etc. driven by the internal combustion engine, which have to be used to assure proper functioning of the engine under all load conditions, reduce the engine eiciency and are for this reason undesirable elements.

Today most large 2-cycle diesel-engines utilize turbosuperchargers to increase the power output. In longitudinal scavenged engines the turbosupercharger is capable to provide sufficient air-pressure to assure scavenging under all load conditions. Suitable exhaust manifolds between the cylinders and the turbine are essential. Furthermore it is possible to advance the exhaust valve opening time at low load in order to increase the available exhaust energy furnished to the turbine. This engine type, which requires exhaust valves and the mechanical complications for changing the valve timing is lundesirable.

To further improve the scavenging conditions different designs of pulse converters have been proposed between the engine cylinder and the exhaust gas turbine intake. These are based on the principle of the jet pump, which utilizes the momentum exchange between gas streams of dierent speed. Even though these pumps are ineicient these devices have shown some gains. i

The instant invention proposes the use of the wave machine described in U.S. application Serial No. 655,441 filed April 26, 1,957, now U.S..Patent No. 3,145,909, entitled Pressure Transformer to F. l. Gardiner and assigned to the assignee of the instant invention, with some modifications and suitable exhaust manifolds to scavenge 2-cycle engines. The cylinders of a multi-cylinder engine can lbe grouped with common exhaust manifolds in such a manner that the blow-down phase of one cylinder does not coincide with the scavenging phase of another cylinder in `the same group. Acylinder of the other group however is in its scavenging phase. The proposed Driver wave machine utilizes the blow-down energy of a cylinder in one group to create a suction effect to one of the cylinders in the other group. The Driver described in aforementioned U.S. application Serial No. 655,441 is capable to convert the temporary pressure rise directly into a temporary vacuum, since inertia effects in wave machines lare practically non-existing for the relatively slow pressure liuctuations as they appear in exhaust pipes of internal combustion engines. The proposed scavenging arrangement for 2-cycle engines can also be used in conjunction with a turbo-supercharger. In the later case the turbo-supercharger raises essentially the pressure level for the engine whereas the wave machine creates the conditions for scavenging.

It is a primary object'of my invention to provide an arrangement whereby the Wave machine is utilized merely to initiate scavenging but does not supply any of .the scavenging air for the reciprocating engine. To this end the wave machine isY utilized only for the purpose of creating the necessary vpressure differential across a cylinder of the reciprocating engine by lowering the exhaust manifold pressure rather Vthan by raising the intake manifold pressure. Thus an object of my invention is to provide a combination of a wave machine and two-cycle multi-cylinder internal combustion enginel wherein the combustion engine has split exhaust manifolds in order to enable the blow-down energy from one cylinder to create the necessary drop in pressure to initiate scavenging in another cylinder. Y

VStill another object of my invention is to provide a wave machine that operates as a pressure transformer with several inlet ports each connected to an exhaust manifold leading to one or more cylinders.

a reciprocating engine and a wave machine whereby the wave machine serves primarily to initiate scavenging of lthe wave machine and the timing of the reciprocating engine automatically controls the operation of the wave machine so scavenging is initiated for the proper cylinder always at the correct time. i 1

These and other objects of my invention will be ap-V parent from the following description when taken in connection with the drawings in which:

FIGURE 1 is a schematic illustration of an example such as a six-cylinder reciprocating engine` connected to Another object is to provide a novel combination ofV y Ya second group C4, C5, C6. connected to a common intake manifold 11 and the first a wave machine by way of a first and second exhaust manifold.

FIGURE 2(a) is a graphic illustration of pressure against time for FIG. 1 illustrating the conditions existing in the first and second manifold E1 and E2 and has superimposed thereon an illustration of which cylinder causes the condition illustrated.

FIGURE-2U?) is a chart showing the conditions existing within the first and second manifold of a six-cylinder engine of FIG. 1 for various degrees of rotation of the reciprocating engine.

FIGURE 3 is a diagrammatic view similar to FIG- URll 1 but shows the manner in which the exhaust gas from the wave machine can be utilized to drive the turbine compressor unit required Yfor supercharging the reciprocating engine.

FIGURE 4(a) is an illustration of the conditions existing within the rotor of the Wave machine when there is blow-down energy provided from one of the cylinders in the first exhaust manifold and when one of the cylinders connected to the second exhaust manifold requires scavenging.

FIGURE 4(b) is an illustration of the conditions existing within the rotor of the wave machine similar to FIGURE 4(cz) but illustrates the conditions when there is blowdown energy from one of the cylinders connected to the second exhaust manifold and when one of the cylinders connected to the tirst exhaust manifold requires scavenging.

FIGURE 4(c) is a state diagram of pressure vs. velocity for the rotor conditions of FIGURES 4(a)and 4(b).

FIGURE 5 is a perspective view ofone form of a rotor that can be used in connection with the embodiments of FIGURES 1 and 3 and shown in the pictorial representation of FIGURES 4(c) and 4(b) in which the rotor has curved channels for superimposing turbine action.

FIGURE 6 is a view of the condition existing within the rotor and is similar to FIGURES 4ta) Vand 4(b) which show a plurality of 360 turns of the rotor and the manner in which the conditions continuously change depending on energy received from the cylinders as well as the requirements of the cylinders for scavenging.

FIGURE 7 is a schematic representation for 4, 5, 6, 7, 8, 9, 10, and 12 cylinder engines illustrating arrangement of common exhaust manifold connections to the wave machine, the sequence of operation, and a diagrammatic illustration of pressure fluctuations.

FIGURE 8 is a schematic perspective View showing the pressure transformer'of aforementioned application Serial No. 655,441; the rotor thereof containing a plurality of cells and also illustrating the dual input and output ports in the stator discs'which are lpositioned on either end of the rotor.

FIGURE 9 is a schematic cross-sectional view showing the rotational mounting of the rotor and the stationary mounting of the stator discs containing the input and output ports.

FIGURE 10 is an end View of a stator disc containing two ports.

FIGURE 11 is a cross-sectional logitudinal section taken through the rotor and stationary disc.

FIGURE 12Y is a cross-sectional view taken along the line 12-12 of the rotor of FIGURE l1 and shows the blades, hub and shroud of the rotor.

Although my invention can be applied to any multicylinder, two-cycle engine, I have chosen to -describe the detailsl of my invention in connection with a six-cylinder engine as set forth in FIGURES 1-6. Specifically referring to FIGURES 1 and 3 the instant invention contemplates a system whereby the cylinders C1, C2, C3, and Both groups are operatively .and second group of cylinders are operatively connected respectively to a first and second exhaust manifold E1,

E2. The first and second exhaust manifolds E1, E2 are operatively connected respectively to a first and second inlet port A, B of the wave machine 20. Wave machine 20 is constructed in the exemplary manner shown in FIGURES 8-12, and operates to provide a pressure differential between certain ones of its ports, as is more fully discussed in aforementioned application Serial No. 655,441. Hence, wave machine 20 operates as a pressure transformer to achieve the advantageous objectives of the instant invention. The rotor 30 is driven at high speed rotation about its axis by any suitable means, such as turbine 31, which is connected to the rotor 30 by shaft 32. The rotor 30 has a hub 34 and an outer shell or shroud 33. A plurality of vanes 36 extend from the hub 34 to the shroud 33, and are permanently secured thereto in any desirable manner, such as brazing.

The space between the vanes 36 forms a plurality of cells or channels 35 through which the uid will ow. The cells or channels 35 may extend parallel to the longitudinal axis of the rotor 30, as shown in FIGURES 8-12, or the vanes 36 may be constructed and positioned so that the resulting cells 33 Wind helically on the rotor 30, as shown in FIGURE 5.

The stator discs or plates 40 and 41 are placed on opposite sides of the rotor 30 in the closest possible proximity thereto consistent with high speed requirements in the rotor to obtain the best possible fluid seal. Input stator disc 40 contains dual input ports A, B, while output stator disc 40 similarly contains output ports C, D. The stator discs orrplates 40 and 41 are rigidly mounted on the base 50, and the rotation of the rotor 30 by the turbine 31 causes the plurality of cells 35 to rotate past the input and output' ports A,'B and C, D respectively.

In either group of engine cylinders at any one instant there will always be a cylinder that is either providing blow-down energy or requires scavenging. This condition will constantly alternate so that the following may be the sequence of operation with respect to time:

240, cylinder C1, supplies blow-down energy, cylinderl C4, to be scavenged 300, cylinder C2, to be scavenged, cylinder C5, supplies blow-down energy Y 360, cylinder C3, supplies blow-downenergy, cylinder C5, to be scavenged.

. Thus, at the two inlet ports A, B of the wave machine 20, one of the two inlet ports receives a supply'of hot exhaust gas under pressure from the reciprocating engine 10 and the remaining inlet port has a reduction of pressure. At any one instant of time there would be a cylinder in one of the two exhaust manifolds that requires scavenging and, simultaneously, there will be a cylinder in the other of the exhaust manifolds that is supplying blown-down energy.

The operation of the wave machine 20, therefore, is such that there is a reduction in the pressure in one of the exhaust manifolds containing a cylinder that should be scavenged. This reduction in pressure creates a pressure differential between the fresh air intake and the exhaust manifold, such that the pressure drop permits scavenging of the cylinder by the fresh air whereby the air has not passed through the wave machine.

It must be noted that, `in orderto achieve the aforementioned results, the cycle of operation of the wave machine 20 is different from the cycles heretofore known. That is, the function and purpose of any one port of the .Wave machine is constantly and continuously changing to be either a high pressure or low pressure port. Even in the heretofore known pressure transfomer of afore- `magnitude of exhaust gasses from mentioned copending U.S. application Serial No. 655,441, l

this condition has not existed. However, as aforementioned, the ports of the wave machine are alternately connected in time to a cylinder that is providing blow-down energy andthence to a cylinder that requires scavenging so that the reversal of pressure of the various ports is automatically provided for the wave machine Ztl by the inherent timing of the reciprocating engine 1t). Furthermore, this continuous reversal of pressure is the result of the pulsating exhaust conditions of the reciprocating engine 1t?. Any cylindergoing through the compression and expansion strokes does not contribute any ow into the exhaust manifold.

In a two-stroke engine 10, the sequence of any one cylinder is as follows: The piston moves up to compress the air contained therein, there is ignition ofthe air-fuel mixture and, thus, the piston is driven downwardly during the expansion portion of the stroke and energy is taken from the reciprocating engine 1t). After about 70 to 80% of the stroke the exhaust ports (valves or ports in the cylinder Wall) are opened up -to release some of the hot gas contained within the cylinder. This is the blow-down portion of the stroke. Before the piston reaches the lowerrnost portion of its stroke, the pressure of the gas within the cylinder is nearly equal to the pressure of the gas in the exhaust manifold. At this time the scavenging ports open. Scavenging is completed when the scavenging ports close.

It should be noted that the wave machinev having, as for instance on six-cylinder engines, ports A and B that are alternately high and low pressure ports is comparable to a pressure transformer rather than a pressure exchanger. Thus, the basic cycle of operation will bear greater similarity to that of aforementioned U.S. application Serial No. 655,441 rather than that of U.S. Patent 2,970,745 issued February 7, 1961, to M. Berchtold entitled Wave Engine and assigned to the assignee of the instant invention or aforementioned U.S. Patent 2,957.- 304. For this reason, the instant invention is clearly distinguishable from that disclosed and claimed in aforementioned U.S. Patent 2,957,304 wherein Ithe reciprocating engine is super-charged by a wave machine which opcrates as a pressure exchanger rather than a pressure transformer and, furthermore, is so connected to the reciprocating engine that it pushes air through the cylinders during scavenging rather than sucking air out of the cylinders during scavenging.

In the embodiment of FIGURE l an arrangement is shown whereby the gas outlet ports C and D are exhausted to the atmosphere and thus, this embodiment is solely for the purpose of assisting scavenging and does not super-charge the reciprocating engine. During'low load or no load operation of the reciprocating engine, the

the reciprocating engine cylinders is extremely low. Thus, in effect, the pressure input to the pressure transformer 2t) at state I is low. Therefore, the second pressure will only be slightly below ambient pressure resulting in a small pressure dierential. As a result, the degree of scavenging will be less. This means that the device has a selfgoverning feature resulting in a larger degree of scavenging during the higher load of the reciprocating engine where it is needed and a reduced scavenging during low load of the reciprocating engine where it is not needed. The same variation of the scavenging exists with the embodiment shown in FIGURE 3 since the degree of scavenging will depend on the magnitude of the blow-down pressure emanating from the reciprocating engine cylinders.

As heretofore noted, the embodiment shown in FlG- URE 1 is exclusively for the purpose of assisting scavenging and does not supercharge the reciprocating engine it?. However, the embodiment of FIGURE 3 not only assists scavenging but also permits super-charging of the reciprocating engine 10. That is, the output of the compressor Si) is at a pressure level above ambient pressure and thus the pressure at the intake manifold 11 is at the same pressure at the intake manifold 11 is at the same pressure as the output of the compressor. It should be noted, however, that the differential in pressure across the reciprocating engine cylinders in the embodiment of FIGURE 3 is substantially the same as the differential in pressure across the cylinders in the embodiment of FIGURE 1. Thus, the same degree of scavenging exists in both the embodiments of FIGURE l and FIGURE 3 but the embodiment of FIGURE 3 also permits super-charging.

In the event the reciprocating engine lil is operated at its optimum power output, it is possible that there wouldV be an excess pressure created at the compressor 59 of FIGURE 3. This surplus pressure applied to the cylinders will now create an increased pressure difference across the cylinders, to thereby further aid in the scavenging operation at the very time Vwhen the best scavenging is desirable.

In the prior art, there is illustrated an arrangement in US. Patent 2,828,103 issued March 25, 1958, to M. Berchtold entitled Non-Steady Flow Turbine and U.S. Patent 2,867,981 issued January 13, 1959, to M. Berchtold entitled Aerodynamic Wave Machine Functioning as a Compressor and Turbine, both of which are assigned to the assignee of the instant application, wherein the configuration of the blades can be utilized to obtain shaft power from a wave machine. Thus, by placing the pressure transformer in axial alignment with the compressor and by utilizing the principles taught in aforementioned US. Patents 2,828,103 and 2,867,981, it is possible to not only (1) assist in the scavenging, and (2) provide supercharging, but also (3) to utilize the excess energy of the pressure transformer to drive the compressor. Thatis, within any one cycle of operation of the drive pressure transformer, the device not only creates the necessary pressure differential across the cylinder, but also produces sufcient excess energy so that a turbine Vaction therein will drive the compressor. Y

In the embodiment of FIGURE l the wave machine 2l) has a continuous cycle of operation such as illustrated in FIGURE 6. Throughout the drawings, a vrepresentation of any one of the six cylinders C in a condition of providing blow-down energy is illustrated by placing a C with a subscript of the specific cylinder both in a square, whereas the condition for a cylinder requiring scavenging is illustrated by the letter C with a sub-script of the Vspecific cylinder both placed in a circle. Therefore, the

illustration of FIGURES 2(a) and 2(b) taken in connection with FIGURES 1 and V4 shows the continuous change of pressure existing in the rst and second exhaust manifold E1 and E2 respectively and FIGURE 6 shows a moving picture of the continuous modification of the conditions within the rotor as the reciprocating engine goes through its complete cycle of operation for all cylinders.

As previously noted, cylinders C1, C2 and C3 are joined to the common exhaust manifold E1 and the second group of cylinders C4, C5 and C6 are joined to a second cornrnon exhaustv manifold E2. Both the manifolds El and E2 are connected to theY wave machine 2h with the exhaust manifold E1 connected to the inlet port Aand the exhaust manifold E2 connected to the inlet port B.

In the illustration of FIGURES 1 and 3, it is assumed that the reciprocating engine has six cylinders and thus ythere would be an angle of 60 and a scavenging period 'of approximately 60. Thus at any time only one cylinder of one group will be providing blow-down energy and one cylinder'of the other group will require scavenging. Thus, if blow-down takes place in one manifold, scavenging occurs in the other manifold. As illustrated in FIGURE 2(a), if there is a high pressure in manifold E1, there is a low pressure in manifold E2 and thus suction will permit scavenging. On the other hand, when the pressure is high in E2, scavenging is required in the manifold El and the necessary suction is available for scavenging one of the cylinders in the first group. Thus, FIGURE 2(a) represents the approximate pressure fluctuations as a function of tirnefor a crank angle of 120 with the dotted line representing the pressure iuctuations in the first exhaust manifold E1 and the solid line representing the pressure uctuationsin the second exhaust manifold E2. The mean pressure is equal to the ambient pressure.

In the embodiment of FIGURE 3 the exhaust gasses of the wave machine emanating alternately from ports C and D are utilized to drive the turbine which, in turn, drives the compressor 50. It isnoted that the wave machine 20 can be used as a direct drive for the compresser by providing the wave machine with short helical rotor channels. Alternately, the rotor could have curved channels as illustrated in FIGURE 5. In :this case, the turbine action is superimposed on the wave action in a simil-ar manner as that described in aforementioned U.S. Patents 2,867,981 and 2,828,103. This turbine has the effect of creating a suction forthe purpose of initiating the necessary scavenging of the reciprocating engine and also provides the necessary shaft power to drive the compressor. The effect of the curved channels can be increased by a larger angle of attack of the gas on the blades.

Particularly for the propulsion of larger ships Z-cycles internal combustion engines with 4, 5, 6, 7, 8,V 9, 10 and l2 cylinders -are being used. The presently proposed system to utilize the blow-down energy in an Aerodynamic Wave machine to induce scavenging can be used on all existing engine configurations.

In each particular case there is arr arrangement best suited. The ypresent specification should be considered as an example showing the principle of operation. FIG- URE 7 illustrates connections and conditions for other 'multi-cylinder engines and the following is a description for each case. In order to simplify lthe description the engine cylinders are numbered in the firing order and not as usual in the order of geometrical arnangement. The description applies to in-line-engines, which means that the crank-angle between the consecutively firing cylinders is always 360 divided by the number of cylinders. It is understood, although not illustrated, that all cylinders have a common intake manifold as previously described in connection with FIGURES l to 6.

4-cylnderV engine Number 1 and 3 cylinder have common exhaust manifold connecting to one laerodynamic wave machine inrcase 90 between cylinders, the blow-down period begins only at a time when the scavenging is well under way. The time for the blow-down period is about 30 whereas the scavenging is about 90". A diagrammatic presentation of the. pressure fluctuation is shown at the right of FIGURE 7. It is therefore necessary -toy support scavenging in the first part by other means. Fortunately it is possible to utilize the rarefaction wave following the blow-down pressure Wave to induce the scavenging. Tuned kexhaust pipes to support scavenging are wellknown. I-t is possible that one manifold leads to several working intake ports in the areodynamic wave rnachine similarly to the present arrangement in the supercharger where 2 cycles are used per revolution.

5 -cylinder engine Each cylinder has its own individual exhaust ypipe leading to a single (or more) intake stator port. There is no common manifold in this case. The blow-down energy of a particular cylinder creates the suction effect for the cylinder running ahead with a crank-angle difference'of- 72; In this case the blow-down and suction periods are nearly simultaneous. The pressure zone rotates from one intake port to the next with the same number of revolutions per minute as lthe engine. The low-'pressure zone isrunning behind with a phase angle of 72. This arrangement however has the disadvantage of a low rotor utilization since there is no -ow in the rotor for 3 out of 5 time intervals. However it will assure sufficient scavenging since the. suction period always follows the blow-down period immediately. If lthe rotor is brought up to speed during start up, scavenging will be assured. This will be an important feature for all configurations.

. 7-cylnder engine This arrange-ment is identical to the S-cylindrer engine arrangement; inasmuch as each cylinder has its indivi-dual exhaust pipe leading to its own intake stator port.

8-eylinder engine Two separate areodynamic Wave machines will be used,.one for each 4-cylinders, having 90 crank-angles. This makes it the identical case as described above. An alternate hood-up with a single aerodynamic wave machine having 4 intake ports combining cylinders 1-5, l2-6, 3-7, 4-8 (as shown i-n FIGURE 7) is also possible.

9-cylinder engine Groups of E',Y cylinders have a common manifold leading to one intake stator port of the areodynamic Wave machine. According to the firing order, cylinder numbers l-4-7, 2-5-8, 3-6-9 are from the 3 groups. Each group has one intake stator port. It is also possible to have pairs of simultaneous working cycles.Y In this case, each manifold is connected to two intake stator ports. The pressure zone rotates in this case 3 times for each revolution for the engine.

10-c'ylinder engine Two separate areodynamic wave machines with each having five individual exhaust pipes land intake stator ports. The arrangement is identical to `the case described for 5-cylinders. An alternate hook-up with a single aerodynamic Wave machine having 5 intake ports combining cylinders 1 6, 2-7, 3-8, 4-9, and 5-10 can also be used.

Two separate areodynamic wave machines are used, each one connected to 6 cylinders. This case is identical to the detailed description in the specification.

Thus, in essence, I have provided a novel arrangement utilizing non-steady ow effects to initiate scavenging of the cylinders of an internal combustion engine. Due to the direct exchange of energy, there is a minimum of losses. Thus, even at low load, a small amount of available exhaust energy is suicient 4to initiate the small degreer of scavenging that would be required on this load.

The arrangement described in the aforementioned U.S. Patents 2,970,746 and 2,957,304 requires that the ambient air be compressed by the exhaust gasses in the rotor and, thus, the air will be heateddue to contact with the rotor and also will be partially contaminated due to the mixing at the intervals between the cold air and the hot gas. These undesirable characteristics are completely eliminated in my novel combination of a pressure exchanger and a reciproating engine having split exhaust manifolds.

Furthermore, with my present arrangement a differential in pressure across the cylinders initiates the scavenging. Thus scavenging by `a vacuum on the exhaust side of the cylinder requires little energy since the remaining gasvquantity in the cylinder is less with a lower pressure.

Although I have described preferred embodiments of my novel invention, many variations and modifications will now be obvious to those skilled in the art, and I '9 prefer therefore to be limited not by the specific disclosure herein but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed vare defined as follows:

l. A Wave machine to initiate the scavenging of a reciprocating engine, said reciprocating engine having a first and second group of cylinders, said first group of cylinders being connected to a first exhaust manifold; said second group of cylinders being connected to a second exhaust manifold; said wave machine comprised of a rotor in a housing, said housing having a first and a second inlet port on one side thereof; said housing also having a rst and a second exhaust port on the other side thereof; said rotor including passage therethrough, interconnecting said inlet and exhaust ports; means for rotating said rotor; said first exhaust manifold being operatively connected to said first inlet port; said second exhaust manifold being operatively connected to said second inlet port; said wave machine first and second ports providing a pressure differential effective to alternately lower the exhaust pressure of said first and second exhaust manifolds.

2, A wave machine to initiate the scavenging of a reciprocating engine, said reciprocating engine Vhaving a rst and second group of cylinders; said first group of cylinders being connected to a first exhaust manifold; said second group of cylinders being connected to a second exhaust manifold; said Wave machine comprised of a rotor in a housing, said housing having a first and a second inlet port on one side thereof; said housing also having a first and a second exhaust port on the other side thereof; said rotor including passages therethrough, interconnecting said inlet and exhaust ports; means for rotating said rotor; said first exhaust manifold being operatively connected to said first inlet port; said second exhaust manifold being operatively connected to said second inlet port; said wave machine first and Vsecond ports providing a pressure differential effective to yalternately lower the exhaust pressure of said first and second exhaust manifolds; said rotor having at least one outlet port on the other side thereof.

3. A combination of a Wave machine and a reciprocating engine; said reciprocating engine having a first andV second group of cylinders, a common intake manifold and a first and second exhaust manifold; said common intake manifold being operatively connected to both said first and second group of cylinders; said first group of cylinders being operatively connected to said first exhaust manifold; said second group of cylinders being operatively connected to said second exhaust manifold; said Wave machine being a pressure transformer having a rotor in a housing, said housing having a first and a second inlet port on one side thereof; said housing also having a first and a second exhaust port on the other side thereof; said rotor including passages therethrough, interconnecting said inlet and exhaust ports; means for rotating said rotor; said first exhaust manifold being operatively connected to said first inlet port `and said second exhaust manifold being operatively connected to said second inlet port; said Wave machine first and second ports providing a pressure differential effective to alternately lower the exhaust pressure of said first and second exhaust manifolds. Y

4. A wave machine to initiate the scavenging of a twocycle reciprocating engine, said wave machine having a rotor in a housing, Said housing having a rst and a second inlet port on one side thereof; said housing also hav-Y ing a rst and a second exhaust port on the other side thereof; said rotor including passages therethrough, interconnecting -said inlet and exhaust ports; means for rotating said rotor; said two-cycle reciprocating engine having a first and second group of cylinders; said first group of cylinders being selectively connected to said first Y inlet port; said second group of cylinders being selectively connected to said second inlet port.

5. A wave machine to initiate the scavengingV of a two-cycle reciprocating engine, said Wave machine having a rotor in a housing, said housing having a first and a second inlet port on one side thereof; said housing also having a rst and a second exhaust porton the other side thereof; said rotor including passages therethrough, interconnecting said inlet and exhaust ports; means for rotating said rotor; said two-cycle reciprocating engine having a first and second group of cylinders; said first group of cylinders being selectively connected to said first inlet port; said second group of cylinders being selectively connected to said second inlet port; said first and second group of cylinders each comprising cylinders Vwhich alternate between supplying blow-down energy to said inlet ports and require low pressure for scavenging.

6. A Wave machine to initiate the scavenging of a ivo-cycle reciprocating engine, said Wave machine having a rotor in a housing, said housing having a first and a second inlet port on one side thereof; said housing also having a first and a second exhaust port on the other side thereof; said rotor including passages therethrough, interconnecting said inlet and exhaust ports; means for rotating said rotor; said two-cycle reciprocating engine having a first and second group ofV cylinders; said first group of cylinders being selectively connected to said first inlet port; said second group of cylinders being selectively connected to said second inlet port, each cylinder Vof said first .and second group of cylinders supplying blow-down energy directly to said inlet ports.

7. A wave machine to initiate the scavenging of a two-cycle reciprocating engine, said Wave machine hav-l ing a rotor in a housing, said housing having a first and v'a second inlet port on one side thereof; said housing also having a'first and a second exhaust port on the other side thereof; said rotor including passages therethrough, interconnecting said inlet and exhaust ports; means for rotating said rotor; said two-cycle reciprocating engine two-cycle reciprocating engine, said wave machine hav- I ing a rotor in 4a housing, said housing having a first and a second inlet port on one side thereof; said housing also e having a first and a second exhaust port on the other side thereof; said rotor including passages therethrough, in-

terconnecting said inlet and exhaust ports; means for rotating said rotor; said two-cycle reciprocating engine having a first and second group of cylinders; said first group of cylinders beingV selectively connected to said first inlet port; said second group of cylinders being selectively connected to said second inlet port; said first inlet port having alternate high and 'low pressure fields; said secondinlet port having alternate high and low pressure fields; said first and second outlet port being alternately ports for no flow of uid and exhaust of fluid from said wave machine,

References Cited by the Examiner UNITED STATES PATENTS 745,703 12/03 Westinghouse 60-32 2,542,756 2/51 Draminsky c 123-65 2,5 8 1,668 1/ 5 2 Kadenacy -123-65 2,888,800 6/59 DenSham vl60--32 RICHARD B.y WILKINSON, Primary Examiner.. JULIUS E. WEST, Examiner. 

1. A WAVE MACHINE TO INITIATE THE SCAVENGING OF A RECIPROCATING ENGINE, SAID RECIPROCATING ENGINE HAVING A FIRST AND SECOND GROUP OF CYLINDERS, SAID FIRST GROUP OF CYLINDERS BEING CONNECTED TO A FIRST EXHAUST MANIFOLD; SAID SECOND GROUP OF CYLINDERS BEING CONNECTED TO A SECOND EXHAUST MANIFOLD; SAID WAVE MACHINE COMPRISED OF A ROTOR IN A HOUSING, SAID HOUSING HAVING A FIRST AND A SECOND INLET PORT ON ONE SIDE THEREOF; SAID HOUSING ALSO HAVING A FIRST AND A SECOND EXHAUST PORT ON THE OTHER SIDE THEREOF; SAID ROTOR INCLUDING PASSAGE THERETHROUGH, INTERCONNECTING SAID INLET AND EXHAUST PORTS: MEANS FOR ROTATING SAID ROTOR: SAID FIRST EXHAUST MANIFOLD BEING OPERATIVELY CONNECTED TO SAID FIRST INLET PORT; SAID SECOND EXHAUST MANIFOLD BEING OPERATIVELY CONNECTED TO SAID SECOND INLET PORT: SAID WAVE MACHINE FIRST AND SECOND PORTS PROVIDING A PRESSURE DIFFERENTIAL EFFECTIVE TO ALTERLNATELY LOWER THE EXHAUST PRESSURE OF SAID FIRST AND SECOND EXHAUST MANIFOLDS. 